as) United States
`a2) Patent Application Publication 10) Pub. No.: US 2016/0278160 Al
`
`
`(43) Pub. Date:Schliwa-Bertlinget al. Sep. 22, 2016
`
`US 20160278160A1
`
`(54) NETWORK NODES, A USER EQUIPMENT
`AND METHODS THEREIN FOR
`ESTABLISHING A CONNECTION BETWEEN
`THE USER EQUIPMENT AND A WIRELESS
`COMMUNICATIONS NETWORK
`
`(71) Applicant: Telefonaktiebolaget L M Ericsson
`(publ), Stockholm (SE)
`
`(72)
`
`Inventors: Paul Schliwa-Bertling, Ljungsbro (SE);
`Thomas Walldeen, Linképing (SE);
`Stefan Johansson, Linképing (SE);
`Hakan Axelsson, Linképing (SE)
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`HOAW 76/06
`HO4W 48/10
`HO4W 48/02
`(52) U.S.CL
`CPC veesescccsees HO4W 76/06 (2013.01); HO4W 48/02
`(2013.01); HO4W 48/10 (2013.01)
`
`(2006.01)
`(2006.01)
`(2006.01)
`
`(21) Appl. No.:
`
`14/891,863
`
`ABSTRACT
`67)
`A methodperformed by a wireless device for handling sus-
`pension of a connection between the wireless device and a
`wireless communications network. The wireless communi-
`cations network comprises the first network node.
`The wireless device receives information from the first net-
`Oct.20, 2015
`(22) PCT Filed:
`
`
`(86) PCT No.: work node. The information comprisesafirst identifier iden-PCT/SE2015/051111
`tifying a first cell area. The first cell area comprises one or
`§ 371 (¢)(),
`more cells capable of resuming the connection.
`
`(2) Date: The wireless device suspends the connectioninafirst cell outNov. 17, 2015
`
`of the one or morecells.
`Related U.S. Application Data
`Whenselecting a cell access method for a cell the wireless
`(60) Provisional application No. 62/079,821, filed on Nov.
`device determines whether or not resumption of the connec-
`14, 2014, provisional application No. 62/069,382,
`tion is allowedin the cell based on the information from the
`filed on Oct. 28, 2014.
`network node.
`
`
` (un
`101, RA msg1
`
`102. RA msg2
`103, RA msg3
`
`104. RA msg4¢
`
`(RRC Connection Setup)
`105. RRC Connection Setup
`(NAS Service Request)
`
`
`107. S1-AP Initial UE msg
`
`
`(NAS Service Request)
`
`
`108. $i-AP Initial Ctxt Setup Request
`
`109. RRC Security Mode Command
`
`
`110. RRC Security Mode Complete.
`111. RRG Connection
`
`Reconfiguration
`112. RRC Connection
`Reconfig complete
`113. S1-APInitital Ctxt Setup
`Co
`
`114. Modify Bearer
`
`Request
`115. Modify Bearer
`
`Response
`
` 116. UL data
`
`
`
`
`
`
`
`
`Sometime elapses -> Timeout
`|
`
`
`120. S$1-AP UE Ctxt Release
`Req
`
`
`121, Release Access Bearers fied
`122, Release Access Bearers Resp
`123, $1-AP UE Ctxt Release Cmd
`
`124. RRC Connection Release
`
`
`
`125. S1-AP UE Ctxt Release Spmpl
`
`119. DL data
`
`117. UL data
`118. DL data
`
`1
`
`APPLE 1006
`
`1
`
`APPLE 1006
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 1 of 33
`
`US 2016/0278160 Al
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`
`
`
`101. RA msg1
`
`
`
`
`102. RA msg2
`
`103. RA msg3
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`104. RA msg4
`
`(RRC Connection Setup)
`
`105. RRC Connection Setup Compleje
`(NAS Service Request)
`
`
`107. S1-APInitial VE msg
`
`(NAS Service Request)
`
`
`
`1-APInitial Ctxt Setup Request
`
`109. RRC Security Mode Command
`
`
`
`
`
` 116. UL data
`
`110. RRC Security Mode Complete
`
`
`
`111. RRC Connection
`Reconfiguration
`112. RRC Connection
`Reconfig complete
`
`119. DL data
`
`
`113. S1-AP Initital Ctxt Setup Compl
`
`
`
`
`
`
`
`Sometime elapses -> Timeout
`|
` 120. S1-AP UE Ctxt Release eq
`121. Release Access Bearers pied
`122, Release Access Bearers Resp
`
`114. Modify Bearer
`Request
`115. Modify Bearer
`Response
`
`117. UL data
`
`118. DL data
`
`124. RRC Connection Release
`
`123, S1-AP UE Ctxt Release Cmd
`
`125. S1-AP UE Ctxt Release Compl
`ST
`Fig.
`1
`
`2
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 2 of 33
`
`US 2016/0278160 Al
`
`200
`
`
`
`3
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 3 of 33
`
`US 2016/0278160 Al
`
`200
`
`ncy
`
`
`RAS Se VF .
`
`VESCs SS
`oe
`fee
`~
`eee
`Feed
`hoe aa
`SS a
`ake
`:
`SOS
`281 CS
`is
`
` 611'~ ffrs
`
`Xx
`
`<
`
`o
`293
`
`4
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 4 of 33
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`US 2016/0278160 Al
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`260
`
`UE context related to connection 251
`
`context
`
`Security
`context
`
`Bearer
`
`Resume
`ID
`
`70
`
`Fig. 2c
`
`5
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 5 of 33
`
`US 2016/0278160 Al
`
`SGW
`
`
`
`
`
`313. Modify Bearer Request
`
`
`
`301. RA msg1
`
`302. RA msg2
`
`
`
`
`
`
`Reconfiguration
`311. RRC Connection
`
`Reconfig complete
`
`
`
`303. RA msg3
`(RRC Connection Request}
`
`
`304. RA msg4
`
`
`(RRC Connection Setup)
`
`305. RRC Connection Setup Complete
`(NAS Service Request)
`
`
`
`306. S1-AP Initial UE msg
`
`(NAS Service Request)
`
`
` 08. RRC Security Mode Command
`
`309. RRC Security Mode Complete
`310. RRC Connection
`
`
`
`
`
`
`_ 316. DL at po
`
`312. S1-AP Initital Ctxt Setup Compl
`
`315. UL data
`
`314. Modify Bearer Response
`
`Sometime elapses -> Timeout
`
`317. S1-AP UE Ctxt Deactive
`rd
`318. S1-AP UE Ctxt Deactive Ack
`
`
`
`
`
`320. RRC Connection Suspend
`(Resume Id, Resume Area)
` 321. Bearer Suspended
`
`Hee ee319.Suspend Bearer==
`(to suspend DL traffic)
`
`Fig. 3
`
`6
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 6 of 33
`
`US 2016/0278160 Al
`
`
`
`
`
`
`401. RA msgi
`
`402. RA msg2
`
`403. RA msg3
`RRC Connection Resume Request
`ResumeId, Auth token(UE), Bearer Ind,Est Cause)
`404. RRC Connection Resume Pending
`(C-RNTI,Resume Id))
`405. RRC Connection Resume Complete
`|
`(Bearer description)
`(If no Pending message also: C-RNTI, Resume ld)
`Encryption Started using ‘old key’, ULtraffic enabled
`
`(torresume DL traffic)
`411. DL data
`
`408. UL data
`
`409. S1-AP UE Ctxt Active Ack
`
`410. Bearer Resume Ack
`
`Some lime elapses -> Timeout
`412. $1-AP UE Cixt Deactive
`SF
`413. S1-AP UE Ctxt Deactive Ack
`
`
`
`
`
`(to suspend DL traffic)
`
`
`
`
`415. RRC Connection Suspend
`(Resume Id, Resume Area)
` 416. Bearer Suspended
`
`j= = eK ee Ke Ke Ke Ke Kee Re ee te ae ae ee ee Ke
`
`Fig. 4a
`
`7
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 7 of 33
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`US 2016/0278160 Al
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`240
`
`211
`
`212
`
`
`401b.RA msg1
`Preamble
`
`Response
`
`
`
`
`
`RRC Connection Resume Request
`(Resume Id, Auth token(UE), Bearer Ind(keep suspended), Est Cause)
`_ _ 404b.RRC Connection ResumePending ___
`(C-RNTI,ResumeId)})
`405b.RRC Connection Resume Complete
`(Bearerdescription)
`(If no Pending message also: C-RNTI, Resume Id)
`Encryption Started using ‘old key’, UL signalling traffic enabled
`
`
`
`406b.S1-AP UE Cixt Active
`(Bearers suspended)
`407b.S1-AP UE Ctxt Active Ack
`
`408b.NAS message UL
`
`409b.NAS message DL
`
`Sometime elapses -> Timeout
`
`
`410b.S1-AP UE Ctxt Deactive
`
`411b.S1-AP UE Ctxt Deactive Ack
`
` 412b.RRC Connection Suspend
`
`(Resume Id, Resume Area)
`
`Fig. 4b
`
`8
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 8 of 33
`
`US 2016/0278160 Al
`
`240
`
`11
`
`21221
`
`401c.RA msg1
`Preamble
`
`Response
`
`RRG Connection Resume Request
`(Resume Id, Auth token(UE),
`Bearer Ind(keep suspended),Est Cause)
`404c.RRC Connection Resume Pending
`(C-RNT|,Resume Id))
`405c.RRC Connection Resume Complete
`(Bearer description)
`(If no Pending message also: C-RNTI, ResumeId)
`Encryption Started using ‘old key’, UL signalling traffic enabled
`406c.S1-AP UE Cixt Active
`(Bearers suspended)
`407c.S1-AP UE Ctxt Active Ack
`
`408c.NAS message UL
`
`|
`
`UE wants to send payload
`
`|
`
`410c.RRC Connection Reconfiguration msg
`(Bearers to be resumed)
`
`
`409c.NAS message DL
`416c.Bearer Resume Ack
`
`413c.RRC Connection Reconfiguration Complete
`
`414c.UL data
`
`411c.S1-AP UE Cixt Active
`(Bearers active)
`412c.Bearer Resume
`
`(to resume DL traffic)
`
`415c.S1-AP UE Citxt Active Ack
`
`Sometime elapses-> Timeout
`!
`
`417c.S1-AP UE Ctxt Deactive
`
`418c.S1-AP UE Ctxt Deactive Ack
`
`(Resume Id, Resume Area)
`
`419c.RRC Connection Suspend
`
`Fig. 4c
`
`9
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 9 of 33
`
`US 2016/0278160 Al
`
`401d.RA msgi
`Preamble
`
`402d.RA msg2
`Response
`
`403d.RA msg3
`RRC Connection Resume
`Request
`(RAN Id, Auth token(UE),Est
`Cause, 'Not same eNB’flag)
`
`404d.RRG Connection Resume
`
`Pending
`(G-RNTI,RANid)
`
`405d.RRC Connection Resume
`Req addition
`(Global eNB Id (PLMN, eNB id))
`
`406d.Transparent message Fetch UE Context
`(Global old eNB Id, RAN Id, New eNB Ref)
`
`407d.Transparent message UE Context transfer
`(Global new eNB id, New eNB Ref, Context)
`
`408d.S1AP Path
`Switch Request
`
`409d.Modify
`Bearer Request
`
`Bearer Response
`
`411d.S1AP Path
`
`Switch Response
`412d.UE Context Release
`
`(Global old eNB Id, RAN Id)
`
`(Bearer descriptions, Auth(NW))
`
`413d.RRC Connection Resume
`Complete
`
`|
`i
`
`Encryption Started using ‘old key’, UL and DLtraffic enabled |
`i
`i
`
`Fig. 4d
`
`10
`
`10
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 10 of 33
`
`US 2016/0278160 Al
`
`vySy,
`ae
`/ 500, UE in RRC Connected Mode \
`\
`(Bearers setup etc}
`}
`
`
`
`“
`we
`
`i
`ae
`
`2
`we
`
`S07. Network wants to and
`‘Connected Mode’
`
`Do a normal STAP UE
`RR. Does UE support
`>No» Context Release and RRC
`<
`_
`~ Suspend/Resume
`mn
`we
`
`Release.
`
`503. Request deactivation of UE Context
`in MME
`
`
`
`Do a normal STAP VE
`” Release.
`
`Yes
`
`50a. Suspend bearers DL in SGW
`and 505b. Suspend UE
`
`
`4=
`i“506 UEin Idie Mode, but suspended \
`((Bearers and securty context from previous |
`
`on
`=
`
`any
`
`My,
`
`,
`
`“e,
`
`session remembered,}
`.
`
`\
`~~
`aeee
`Og “
`Fig. 5
`
`;
`!a
`a
`
`11
`
`11
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 11 of 33
`
`US 2016/0278160 Al
`
`
`
`600, UE in idie Mode, but suspended
`f
`{KS {RearersAnd security contextfrom previoussEssion remembered}
`
`>
`}
`
`807. UE wants ia contact network
`
`
`——
`
`ee
`BORUE
`support SRand
`Pa
`>
`603b. UE to do a normal
`me
`Resume 1D LN snags
`exctatilies
`service astabishment
`"a
`a
`
`~ Vali
`_ow
`.
`owes
`Veg
`603. UE makes a random access and provides an
`RRC Connection Resume Request with resumeid,
`avi aulheniication icken, indication if bearers should
`
`be resumed and establishment cause ae
`
`No
`
`~
`
`Me,
`605a, eNodedrejectsthe alternp!
`boa. Acceso.
`with an Indication of when UE
`— atiemot accented me
`
`[earliest can retry again. (can use
`SE Se
`oe
`~ byeNodeB
`resume again)
`we
`a
`
`aaa
`
`Yes
`é06a. eNodeb rejects the atiernpt with an
`ao
`indication that a normal service
`$055, Resume
`a known and ralate4 ue No_we/CStablishement is needed. This can either be
`ON teat
`ann
`done directly with the assigned schedulin
`~
`context ok
`“
`;
`aan
`we
`identity or make a complete new random
`—
`a“
`es
`Sccess.
`
`L__yes
`
`
`806b. UL payload trafic possible.
`
`
`80Sc. eNodeB inflates activation of LIE context in MME.
`
`
`oN
`—
`=
`-
`:
`=
`:
`7
`-
`
`
`Yer
`508b. Connectionip be released in MME and beares in SGW. UE to be
`
`
`released and a new normal service request used instead, This can
`“ Secapted wonNo
`either be done directly with the assigned scheduling identity or makea
`
`“by MMER<
`complete new random access.
`
`
`S08. eNodeB Inifiate resumption of bearers for DL In SGW(UL never suspended)
`(
`809. UE in RRO Gonnected Mode (Bearers setup etc}
`}
`e fa
`Fig. 6
`
`
`
`12
`
`12
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 12 of 33
`
`US 2016/0278160 Al
`
`
`
`Imode
`
`RUD RU ARR RR RR
`
`!
`703. Transmit indication to second
`:
`Inetwork node.
`feet cna catty ttn cata T ven ee ct el
`i 704.Requestthirdnetwork nodeto stop DL data
`Leccecoe|ene oe amen Wwwns ee mse
`705. Store UE context, resumeidQe ARAAARRRRR©GAARA RRA ORAAAAAARRR©RU,
`
`709.Request 2ndnetwork nodeto activate |
`UE context
`]
`
`
`
`Fig. 7
`
`13
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 13 of 33
`
`US 2016/0278160 Al
`
`
`
`801. Receive command
`
`2. Transition to suspendedidle mode
`
`100oO
`
`[e2)oS
`
`3. Transmit first message
`
`8oO4. Receive second message
`
`
`
`Fig. 8
`
`14
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 14 of 33
`
`US 2016/0278160 Al
`
`
`
`secenecens—enenmannnn=cannons=aamannone©enone ‘eencnenner ennennenna _nenonnnent nonnennee ennanneane _ennnanng
`
`
`
`
`
`
`
`
`
`
`
`
`
`901. Receive indication
`
`902. Deactivate UE context
`
`riot
`
`903. Page UE
`
`1904. Activate UE context
`
`
`
`Fig. 9
`
`15
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 15 of 33
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`US 2016/0278160 Al
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`
`
`:| 901a. Receive indication that UE 240 is |
`suspended
`
`202a. Deactivate UE context for UE 240|
`Store UE context
`|
`| Store $1 signalling identifier
`| Command SGW to buffer DL traffictoUE
`|
`
`
`
`Fig. 9a
`
`16
`
`

`

`Patent Application Publication
`
`Sep. 22,2016 Sheet 16 of 33
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`US 2016/0278160 Al
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`
`
`1001. Suspend bearer
`
`1002.Inform2nd networknodeof DL - 4
`
`traffic
`
`1003. Transmit buffered DL data
`
`
`
`Fig. 10
`
`17
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 17 of 33
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`US 2016/0278160 Al
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`
`
`1000. Obtain indication of suspension of UE 240
`
`1001. Suspend bearer
`
`1002. Inform 2nd network node of DL
`traffic
`
`
`
`Fig. 10a
`
`18
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 18 of 33
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`US 2016/0278160 Al
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`211 first network node
`
`1180 Processor
`
`1190 Memory
`
`1150 Commanding
`mod = @
`
`11 oO Timer module
`
`—h 120 Checkingmodule
`
`1130 Transmitting
`3 2°a = Oo
`
`1140 Requesting_module
`
`1160 Recievingmodule
`
`1170 Initiating module
`
`1175 Identifying module
`
`19
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 19 of 33
`
`US 2016/0278160 Al
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`240 wireless device/UE
`
`1210 Receiving module
`
`1220 Transitioning
`module
`
`1290 Memory
`
`1230 Transmitter module
`
`1280 Processor
`
`Fig. 12
`
`20
`
`20
`
`

`

`1310 Receiving module
`
`1320 Deactivating
`modu
`
`1330 Paging module
`
`1380 Processor
`
`1340 Activating module
`
`Patent Application Publication
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`Sep. 22,2016 Sheet 20 of 33
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`US 2016/0278160 Al
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`12 third network node
`
`1390 Memory
`
`Fig. 13
`
`21
`
`21
`
`

`

`1410 Suspending
`odul
`
`1420 Informing_module
`
`1430 Transmitting
`module
`
`1480 Processor
`
`Patent Application Publication
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`Sep. 22,2016 Sheet 21 of 33
`
`US 2016/0278160 Al
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`213 fourth network node
`
`1490 Memory
`
`Fig. 14
`
`22
`
`22
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 22 of 33
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`200
`
`Cell 2-3: RRA=B
`
`
`
`Fig. 15
`
`23
`
`23
`
`

`

`Patent Application Publication
`Sep. 22, 2016
`Sheet 23 of 33.=US 2016/0278160 Al
`
`1600
`
`RRAInformation
`
`1602
`f-
`
`
`
`
`
`RRACV
`
`1601
`
`fV-
`
`
`
`
`
`RRAC
`
`2 bits
`
`RRA Code Version
`
`6 bits
`
`RRA Code
`
`Second RRAInformation
`
`1620
`
`
`
`
`1604
`f-
`
`
`
`
`
`RRACV
`
`1603
`f-
`
`
`
`
`
`RRAC
`
`2 bits
`
`RRA Code Version
`
`6 bits
`
`RRA Code
`
`Fig. 16
`
`24
`
`24
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 24 of 33
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`200
`
`
`
`
`
`
`
`CellA
`Cell B
`
`
`RRAC 111114
`RRAC 111114
`
`
`RRACV:00
`RRACV:00
`
` Cell C
`RRAC 11111
`
`RRACV:00
`
`Fig. 17a
`
`
`
`
`
`
`
`CellA
`Cell B
`
`
`RRAC 111114
`RRAC 111114
`
`
`RRACV:00
`RRACV:00
`
` Cell C
`
`
`RRAC 11111
`RRACV:01
`
`Fig. 17b
`
`25
`
`25
`
`

`

`Patent Application Publication
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`Sep. 22,2016 Sheet 25 of 33
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`
`Action 1801/Step 4
`
`Tn
`
`it
`( RRC Connected
`
`Action 1802/Slep 2
`
`Suspendprocedure|
`RRAslored and |
`| ROVTinitialised
`
`
`
`(PDDDTTTannrrnenrenarrerensegeeeeeeeeeeeeeeeeeeeeet
`
`UE exits
`suspended
`
`
`
`
`Action 1806/Step 6
`
`Acton T805/Step 5
`
`Action 1804/Step 4
`
`Fig. 18
`
`26
`
`26
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`Patent Application Publication
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`Sep. 22, 2016 Sheet 26 of 33
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`/“RRC suspended with®\ Action 1901/
`RRAstored /
`Step1
`KR
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`Rallehanaa (antair,
`g
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`
`Action 1902/
`Step 2
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`_ Trigger for RRC connection
`Step 3
`|
`setup
`\ OO¥ee
`fo
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`Step 6
`
`Fig. 19
`
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`Patent Application Publication
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`Sep. 22,2016 Sheet 27 of 33
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`Fig. 20 Method in UE/wireless device 240
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`Patent Application Publication
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`Sep. 22,2016 Sheet 28 of 33
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`
`
`20014 Receiveidentifier
`
`PE EEE EE EE EEE |
`2002a. Receive timer
`|
`
`ee
`
`2004, Suspend connection
`
`CEE EE EEE EE |
`'2005a. Delete identifier
`
`
`'2006a. Select cell access method
`
`
`
`Fig. 20a Method in UE/wireless device 240
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`Patent Application Publication
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`Sep. 22,2016 Sheet 29 of 33
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`
`eee EE “|
`
`1
`
`|
`21 1. Configure capability of cell, e.g. with
`access to resume information
`Le ee eee!
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`
`2103. Transmit identifier
`2104. Transmit timer CO |
`SO
`'2105.Deleteidentifie#8=8 =~ |
`ee cee sm
`
`—
`
`Fig. 21 Method in network node 211
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`Patent Application Publication
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`Sep. 22,2016 Sheet 30 of 33
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`r2101a. Configure capability of cell, e.g.
`with access to resume information a
`
`
`
`Fig. 21a
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`Patent Application Publication
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`Sep. 22,2016 Sheet 31 of 33
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`240 wireless device/UE
`
`2210 Receiving module
`
`2290 Memory
`
`2220 Transitioning
`module
`
`230 Transmitter module
`
`2280 Processor
`
`2240Suspending
`module
`
`2250 Deleting module
`
`2260 Selecting module
`
`Fig. 22
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`Patent Application Publication
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`211 first network node
`
`2301 Configuring module
`
`2310 Timer module
`
`2302 Identifying module
`
`2320 Checkingmodule
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`2303 Suspending
`module
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`2304 Deleting module
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`2330 Transmitting
`module
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`2340 Requesting
`module
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`Sep. 22, 2016 Sheet 32 of 33 US 2016/0278160 A1
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`2350 Commanding
`module
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`360 Recievingmodule
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`2370 Initiating module
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`2380 Processor
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`2390 Memory
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`Fig. 23
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`214 second network node
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`2430 Transmitting
`module
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`2480 Processor
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`2490 Memory
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`Fig. 24
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`US 2016/0278160 Al
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`Sep. 22, 2016
`
`NETWORK NODES, A USER EQUIPMENT
`AND METHODS THEREIN FOR
`ESTABLISHING A CONNECTION BETWEEN
`THE USER EQUIPMENT AND A WIRELESS
`COMMUNICATIONS NETWORK
`
`TECHNICAL FIELD
`
`[0001] Embodiments herein relate to a network node, a
`wireless device, a system of network nodes and methods
`therein. In particular the embodiments herein relate to han-
`dling a connection betweenthe wireless device and a wireless
`communications network.
`
`BACKGROUND
`
`[0002] Communication devices such as terminals are also
`known as e.g. User Equipments (UE), mobile terminals, wire-
`less terminals and/or mobile stations. Terminals are enabled
`communicate wirelessly in a wireless or cellular communi-
`cations network or a wireless communication system, some-
`times also referred to as a cellular radio system or cellular
`network. The communication may be performede.g. between
`two terminals, between a terminal and a regular telephone
`and/or between a terminal and a server via a Radio Access
`
`Network (RAN) and possibly one or more core networks,
`comprised within the cellular communications network.
`[0003] Examples ofwireless communications networks are
`Long Term Evolution (LTE), Universal Mobile Telecommu-
`nications System (UMTS) and Global System for Mobile
`communications (GSM).
`[0004] Terminals may further be referred to as mobiletele-
`phones, cellular telephones, laptops, surf plates or tablets
`with wireless capability,
`just
`to mention some further
`examples. The terminals in the present context may be, for
`example, portable, pocket-storable, hand-held, computer-
`comprised, or vehicle-mounted mobile devices, enabled to
`communicate voice and/or data, via the RAN, with another
`entity, such as another terminalor a server.
`[0005] Thecellular communications network covers a geo-
`graphical area whichis divided into cell areas, wherein each
`cell area being served by an access node such as a basestation,
`e.g. a Radio Base Station (RBS), which sometimes may be
`referred to as e.g. “eNB”, “eNodeB”, “NodeB”, “B node”, or
`BTS (Base Transceiver Station), depending on the technol-
`ogy and terminology used. The base stations may be of dif-
`ferent classes such as e.g. macro eNodeB, home eNodeB or
`pico base station, based on transmission power and thereby
`also cell size. A cell is the geographical area where radio
`coverage is provided bythe base station at a base station site.
`Onebasestation, situated on the base station site, may serve
`one or several cells. Further, each base station may support
`one or several communication technologies. The base sta-
`tions communicate over the air interface operating on radio
`frequencies with the terminals within range of the base sta-
`tions. In the context of this disclosure, the expression Down-
`link (DL) is used to denote the transmission path from the
`base station to the mobile station. The expression Uplink
`(UL)is used to denote the transmission path in the opposite
`direction i.e. from the mobile station to the base station.
`
`In 3rd Generation Partnership Project (GPP) LTE,
`[0006]
`base stations, which maybe referred to as eNodeBs or even
`eNBs, maybe directly connected to one or more core net-
`works and related core network nodes, such as a Mobility
`Management Entity (MME) and a Serwing GateWay (SGW).
`
`[0007] The MMEis a control node andis responsible for
`idle mode UE tracking and paging procedure including
`retransmissions. The MMEis involved in the bearer activa-
`tion/deactivation process and is also responsible for choosing
`the SGW for a UE attheinitial attach and at time of intra-LTE
`handoverinvolving Core Network (CN) noderelocation. The
`MMEisresponsible for authenticating the user.
`[0008]
`3GPPLTE radio access standard has been written in
`order to support high bitrates and low latency both for uplink
`and downlink traffic. All data transmission is in LTE con-
`trolled by the radio basestation.
`[0009] The introduction of new types of devices, such as
`devices that are used for Machine-Type-Communication
`(MTC), that interact with wireless communications networks
`put new requirements both on the devices, such as UEs, and
`the networks. Such new requirements may impose problems,
`such as shorter battery lifetime for the UEs, and from the
`network point of view one of the problemsis to handle many
`devices sending small amounts of data.
`[0010]
`For example, when a device, such as a UE, wants to
`send data, it needs to set up a connection towardsthe wireless
`communications network. This implies some mandatory
`steps, e.g. establishing a control connection to the MME
`through the eNodeB, establishing a secure radio connection
`on the air interface and configuring data bearers through
`which data maybe sent. FIG. 1 shows a legacy normalservice
`request establishment in LTE when data is to be received or
`transferred. As can be seen from FIG. 1 there is rather much
`
`signaling, i.e. actions 101-114, before the UE sends 115 the
`payload data to the eNodeB.
`[0011] The signaling described above consumes muchpro-
`cessing resources comparedto the data volume being trans-
`ferred for some devices, such as MTCs. This may then set a
`limit on how many devices that an eNodeB may handle, or
`how muchothertraffic the eNodeB may handle.
`[0012]
`Oneprior art approach is to always have the devices
`in connected mode, that is e.g. have a control connection
`towards the MME,a secure radio connection and configured
`data bearers established all the time. This will however have
`
`impacts both on the performance of mobile devices, e.g. in
`termsofbattery lifetime, and also on the performance of the
`network, since the connected mode consumes network
`resources. In fact, an eNodeB is normally designed to only
`handle a certain maximum number of users in connected
`
`mode. Since the actual numberof devices in the area may be
`multiples higher than the designed maximum numberofusers
`in connected modethis will imposea large limitation.
`
`SUMMARY
`
`It is therefore an object of embodiments herein to
`[0013]
`address at least some of the problems and issues mentioned
`above, by providing an improved wayof handling a connec-
`tion between a wireless device and a wireless communica-
`tions network.
`
`[0014] When a connection between the UE, i.e. wireless
`device, and the network is released in LTE,all contexts in the
`eNodeB andthe related information in the MME and the
`SGWarereleased. At the next service request, e.g. when the
`UE wants to send data, the entire signaling procedure for
`establishing a connection needs to be performedagain.
`[0015] The current way to alwaysestablish a new connec-
`tion leads to much signaling and hence consume muchpro-
`cessing resources comparedto the data volume being trans-
`ferred for some devices, such as MTCs.
`
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`US 2016/0278160 Al
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`Sep. 22, 2016
`
`Instead of releasing an established connection
`[0016]
`between a wireless device, such as the UE, and the wireless
`communications network, the wireless device is ‘suspended’
`in embodiments herein. Suspended meansthat datarelated to
`the established connection between the wireless device and
`the wireless communications network are saved in the wire-
`less device and in network nodes connected to the wireless
`device, such as an eNodeB, an MMEand an SGW.
`[0017] The data may comprise a UE context, for example a
`UEcontext related to security, bearers, Temporary Interna-
`tional Mobile Subscriber Identity (T-IMSI) and UEcapabili-
`ties.
`
`Further, in embodiments herein, instead of estab-
`[0018]
`lishing a new connection betweenthe wireless device and the
`wireless communications network whenthere is new data to
`be transferred, the previous connection is resumed,or contin-
`ued, at a later time with the same security context and bearers.
`[0019]
`In other words, in embodiments herein the wireless
`device may be connected to the wireless communications
`network using the same connection parameters for several
`sessions of the connection since these connection parameters
`are saved in the wireless device and in the network nodes
`during the above suspension of the connection.
`[0020] The wireless device is in other aspects handledas in
`“Idle mode’. Although the wireless device is in other aspects
`handled as in ‘Idle mode’, the wireless device may continue a
`previous session of the connection, i.e. ‘resume the previous
`session’ when the wireless device wants to establish a con-
`
`nection towards the network, e.g. when there is new data to be
`transferred.
`
`[0027] The wireless device receives information from the
`first network node. The information 1600 comprisesa first
`identifier identifying a first cell area. The first cell area 281
`comprises one or more cells capable of resuming the connec-
`tion.
`[0028] The wireless device suspends the connection in a
`first cell out of the one or morecells.
`
`[0029] When selecting a cell access method for a cell the
`wireless device determines whetheror not resumption of the
`connection is allowed in the cell based on the information
`from the network node.
`
`[0030] According to a second aspect of embodiments
`herein, the object is achieved by a method performedbya first
`network node for handling suspension of a connection
`between a wireless device and a wireless communications
`network. The wireless communications network comprises
`the first network node.
`
`Thefirst network nodeidentifies a first cell area. The
`[0031]
`first cell area comprises one or more cells capable ofresuming
`the connection when the connection is suspended.
`[0032]
`Thefirst network node transmits information to the
`wireless device, which information comprisesa first identifier
`identifying the first cell area. The information enables the
`wireless device to determine whether resumption of the con-
`nection is allowedor not in a cell.
`
`Thefirst network node suspends the connection in a
`[0033]
`first cell out of the one or morefirst cells.
`
`[0034] According to a third aspect of embodimentsherein,
`the object is achieved by a wireless device configured to
`perform the method accordingto thefirst aspect.
`[0035] According to a fourth aspect of embodiments
`[0021] The ‘Resume’ of the previous connection may be
`allowed within the cell where the wireless device was ‘sus-
`herein, the object is achieved bya first network node config-
`ured to perform the method according to the second aspect.
`pended’ or in a cell in which information indicating that
`resumeis possible is broadcasted.
`[0036] According toafifth aspect of embodiments herein,
`[0022] Embodimentsherein are related to such information
`the object is achieved by a method performed by a system of
`indicating whetheror not resumeis possible.
`network nodes for suspension of a connection between a
`wireless device and a wireless communications network. The
`[0023]
`In order for the UE to be able to resume its RRC
`wireless communications network comprises the system of
`connection, a set of parameters, e.g. the UE’s security con-
`network nodes.
`text, also referred to as ‘RRC Resume Context’ or ‘UE Con-
`text’ herein, and a resumeidentifier of the UE, may be needed
`to be available to the cell that the UE wants resume its RRC
`
`[0037] A first network node comprised in the system of
`network nodesidentifies a first cell area. The first cell area
`
`comprises one or more cells capable of resuming the connec-
`connection with. These parameters will be further explained
`tion when the connection is suspended.
`in the detailed description below.
`[0038]
`Thefirst network node transmits information to the
`[0024]
`Furthermoreit is fair to assume that due to typical
`
`network deployments a given RRC Resume Context and a wireless device. The information comprisesafirst identifier
`resume identifier of the UE will only be available to cells
`identifying thefirst cell area.
`within some limited geographical area. Therefore a UE
`[0039]
`Thefirst network node suspends the connection in a
`first cell out of the one or morecells.
`attempting blindly to resume its RRC connection with an
`arbitrary cell that may or may not have access to the RRC
`Resume Context will result in a high rate of resume attempt
`failures wasting the UEs’ battery lifetime, radio resources,
`network resources, such as Random Access bandwidth, or L3
`signalling load or node CPU cycles and increasing the inter-
`ferencelevel.
`
`[0040] A second network node comprisedin the system of
`network nodestransmits a second information to the wireless
`device. The second informationis related to a cell. The second
`
`information comprisesa third identifier identifying a second
`cell area. The second cell area comprises the cell. This
`enables the wireless device to determine whether or not
`resumption of the connection is allowedin the cell based on
`Finally, storing the RRC Resume Contextsinfinitely
`[0025]
`comparing the first information with the second information.
`may cause memory exhaustion in the UE and in network
`nodes involved in RRC Resume, which impacts the network
`[0041] According to a sixth aspect of embodimentsherein,
`performance.
`the object is achieved by a system of network nodes config-
`ured to perform the method above performedby the system of
`[0026] According toafirst aspect of embodiments herein,
`network nodes.
`the object is achieved by a method performed by a wireless
`device for handling suspension of a connection between the
`wireless device and a wireless communications network. The
`wireless communications network comprises the first net-
`work node.
`
`[0042] The wireless device receives information compris-
`ing thefirst identifier identifying the one or more cells capable
`ofresuming the connection from thefirst network node. Since
`the wireless device selects a cell access method based on the
`
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`US 2016/0278160 Al
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`Sep. 22, 2016
`
`information comprising thefirst identifier radio resources are
`only spent on cell access attempts that are supported by the
`wireless device and the wireless communications network
`and therefore the performancesofthe wireless device and the
`first network node are improved.
`[0043]
`In other words, since the wireless device selects a
`cell access method based on the information from thefirst
`
`network nodethe performancesofthe wireless device and the
`first network node are improved.
`[0044] Embodiments herein enable a flexible handling of
`RRCconnections.
`
`FIG. 44 is a signaling diagram illustrating further
`[0056]
`embodiments of a method performed in a wireless commu-
`nications network.
`
`FIG. 4c is a signaling diagram illustrating further
`[0057]
`embodiments of a method performed in a wireless commu-
`nications network.
`
`FIG. 4d is a signaling diagram illustrating further
`[0058]
`embodiments of a method performed in a wireless commu-
`nications network FIG.5 is a flowchart illustrating embodi-
`ments of a method performedbya first network node.
`[0059]
`FIG.6 is a flowchart illustrating embodiments of a
`[0045] Embodiments herein enableafaster transition from
`method performed in a wireless communications network.
`‘idle’ to ‘ready to transfer data mode’, such as RRC Con-
`[0060]
`FIG. 7 is a flowchart illustrating embodiments of a
`nected Mode. In embodiments herein no roundtrip commu-
`method performedbya first network node.
`nication towards the core network nodeis needed to set up a
`[0061]
`FIG. 8 is a flowchart illustrating embodiments of a
`connection towards the wireless communications network.
`method performed by a wireless device.
`[0062]
`FIG. 9 is a flowchart illustrating embodiments of a
`method performed by a third network node.
`[0063]
`FIG. 9a is a flowchart illustrating further embodi-
`ments of a method performedbya third network node.
`[0064]
`FIG. 10 isa flowchart illustrating embodiments of a
`method performed by a fourth network node.
`[0065]
`FIG. 10a is a flowchart illustrating further embodi-
`ments of a method performed bya fourth network node.
`[006